Sunday Problem #54

Published 13 Jun 2021 by antti (last edited 26 Jun 2021)

This problem is from the Korean tsumego connection , known in Japan as Tenryūzu. The name might be translated into English as ‘Sky Dragon Diagrams’. Most of the problems in the collection are notoriously difficult, making it good practice material for aspiring professional players.

For this Sunday Problem, I tried to pick a relatively easier problem from the collection.

Black to play.

Solution
Failure
The first obvious move in this problem is the black cut of 1, but, just as obviously, white responds with 2, setting up a kō.
It could be possible that this is the solution to the problem, but, if it was a real game, you would at least want to try to see if there is a way to capture unconditionally before going for this line.
Additionally, since we have the additional context of ‘this is supposed to be a difficult problem’, you can meta-game this problem and assume that this kō probably isn’t the solution.
Solution
There are a number of other ways Black can get a kō, but the only way to avoid a kō is to start with this placement of 1. This aims at the cut of
a next, so white 2 is basically forced.
Following, 3–7 set up a liberty shortage for White, capturing the group unconditionally.

Comments (3)


Tanukki wrote 1 month, 2 weeks ago:

The first move is difficult. My top 3 choices were all wrong, with option #4 I found the answer.


antti wrote 1 month, 2 weeks ago:

I also like the ‘honesty’ of this problem: m18–m19 very obviously creates a ko for White’s life, so assuming that the problem is difficult, there has to be an unconditional kill hiding somewhere.


antti wrote 1 month, 1 week ago:

Solution added.